Device for Cooperative Hand Function Trainings in Rehabilitation and Corresponding Method

ABSTRACT

The invention is directed to a device to train bilateral, cooperative hand functions of a subject with housing means, handle means comprising two exchangeable handles ( 1 ), namely a left handle and a right handle, shaft means comprising multiple shafts and couplings for coupling said shafts ( 2 ), clutching means comprising variable slipping clutches ( 3 ), said slipping clutches being adjustable, first sensor means ( 4 ) for measuring the angular position of each of said handles ( 1 ), second sensor means ( 5 ) for measuring the torque which is applied by the subject onto each of said handles ( 1 ), locking means ( 6 ) for locking said shaft means ( 2 ) wherein both handles can be rotated independently when said locking means are locked, wherein said locking means are positioned between said second sensor means so that said second sensor means for the left handle can measure the torque applied onto the left handle and said second sensor means for the right handle can measure the torque applied onto the right handle when the locking means are locked and said second sensor means for the left handle said second sensor means for the right handle can measure the torque applied onto either of said handles when said locking means are unlocked and bearing means ( 8 ) for said shaft means, said bearing means being mounted to the housing of a device.

FIELD OF THE INVENTION

The invention relates to the field of rehabilitation methods and apparatus for functional training such as stroke.

BACKGROUND OF THE INVENTION

On the basis of animal experiments (1-3) it is well established, also for human beings (for reviews see (4, 5)) that a training should be directed to a specific task to be re-learned. For example, in stroke subjects it should be directed to the specific functions which are most essential for daily living activities.

Most upper limb rehabilitation devices are designed for the training of a single limb and their main goal is to train unilateral reach and grasp movements, a quite important task.

The actually best established approach for hand rehabilitation after a stroke represents the “Constraint-induced movement therapy” in stroke subjects (6) for review see (7). This implies that the patients train the affected limb while the unaffected one is immobilized. Also most assistive devices are designed for an unilateral arm/hand training or a bilateral one (see below) without cooperative movements of the two arms (8-11).

However, there are indications that training effects are more effective, especially for proximal arm muscles function in bilateral compared to unilateral movement approaches (12, 13).

However, none of the existing training devices, are designed to provide bilateral, cooperative hand movements for training. Although, in reality, in a great number of practical reach and grasp tasks, both limbs are required to execute the task in a cooperative manner for execution (e.g. to reach and grasp an egg and to open it over the pan). According to the physiological and anatomical background a close interaction and coordination exists between both hands/arms.

SUMMARY OF THE INVENTION

The invention relates to a device to train in particular bilateral, cooperative hand functions such as opening/closing a bottle or a can. Such daily living tasks are performed in a natural way against different levels of resistance. With this novel device functional training, for example of stroke subjects, can be optimized as it represents a frequently movement task during daily living.

Bilateral training herein means that both hands are involved in a task. Cooperative training means that, during bilateral training, one hand serves/supports the other one for the completion of that task. For example during cooperative training, one hand holds an item and counteracts against the forces exerted on that item by the other hand. This is achieved by the device which couples manipulative movements of both sides. Preferably, the device comprises means to switch between cooperative (i.e. coupled) and bilateral non-cooperative (i.e. un-coupled) training. The device may also be used for unilateral training.

Therefore, in one embodiment of the invention, the device comprises two exchangeable handle portions (1), shaft portions (2) and clutch systems (3) that are structured and arranged to transmit motion from the handle portions to the shaft portions.

In a preferred embodiment, the clutch systems allow adjustment of the resistance force between the shaft portion and the handle portions.

In another preferred embodiment, the device comprises two shaft portions and locking means (6) that is structured and arranged to optionally lock or release the movement of the two shaft portions against each other.

In another embodiment, the device comprises angular rotation sensors (4) to measure the angular position of the handles. In one embodiment, the device comprises a belt (7) to translate the rotation of the handles to the angular rotation sensors.

In a further embodiment, the device comprises torque sensors (5) to measure the torque which is applied by the patient. If the main shaft is locked, the sensors measure only the torque at the left or right side, applied by the left or right hand, respectively. When unlocking the main shaft, both sensors measure the same torque.

In further embodiments, the exchangeable handle portions may have a form of a nut to simulate the movement of putting a screw and a nut together, or a form of a pen to simulate the movement of open/close a screwable pen, or a form of a crank handle, or comprise a lever, or comprise two pin simulating a different crank handle, or comprise a wheel, or a plate, or may simulate a key, or simulate a corkscrew, or simulate the bottom of a bottle or a big handhold, or simulate the upper part of a bottle or a small handhold

In one embodiment, the device comprises a virtual reality system by projecting moving signals on a screen which have to be followed by the subject. In a further expanded version, mainly for the training of stroke subjects, virtual reality is implemented for the training of uni- and bilateral daily living tasks. This implementation of virtual reality comprises fine to gross finger/hand movements.

BRIEF DESCRIPTION OF THE FIGURES

The above mentioned and other features and objects of this invention and the manner of achieving them will become more apparent and this invention itself will be better understood by reference to the following description of various embodiments of this invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows a schematic illustration of an embodiment of a device for cooperative/non-cooperative hand movements

FIG. 2 shows a schematic illustration of a second embodiment of a device for cooperative/non-cooperative hand movements

FIG. 3 shows a technical drawing of an embodiment of a device for cooperative/non-cooperative hand movements

FIG. 4 shows various exchangeable handles of a device for cooperative/non-cooperative hand movements

FIG. 5 shows EMG responses in muscles in both arms following unilateral non-noxious ulnaer nerve stimulation during cooperative training with the device of FIG. 1. A: EMG response in muscles of right arm, B: EMG response in muscles of left arm

FIG. 6 shows EMG responses in muscles in both arms following unilateral non-noxious ulnaer nerve stimulation during non-cooperative training with the device of FIG. 1. A: EMG response in muscles of right arm, B: EMG response in muscles of left arm

DETAILED DESCRIPTION OF THE INVENTION

The novel device allows to train cooperative and non-cooperative movements of either the hand and fingers or the whole arm for rehabilitative purposes. The specific involvement of upper extremity muscles and joints during task completion and mode of bilateral cooperation is determined by the size of the exchangeable handle portions and the task to be performed by a virtual reality presentation and feedback information:

-   -   Fine finger and hand movements are involved by twisting a screw         (one hand) in a nut (other hand or alternative device).     -   Greater movement amplitudes are required to manipulate large         wheels or levers mounted with pawls.     -   Specific interference between the two hands is for example         required to insert a pen in its cover.

Such tasks only require to exchange the handles and the corresponding graphical representation on a screen. The resistant forces between the handle portions and the shaft portions will be adapted to the respective task. In addition, the movement tasks can be expanded by projecting moving signals on a screen which have to be followed by the subject.

In a further expanded version, mainly for the training of stroke subjects, virtual reality is implemented for the training of daily living tasks. This implementation of virtual reality should comprise fine to gross finger/hand movements.

The particular embodiments of the device shown below were chosen in order to have a simple device which allows for unilateral and bilateral (cooperative/non-cooperative) hand movements, respectively, and for sensing the most important biomechanical signals (torque and position of both sides). Bilateral manipulative hand movements become coupled (cooperative) or uncoupled (non-cooperative) by the device. The cooperative movements can be exerted at different force levels. The device allows to train different daily living tasks. Furthermore, the device represents a very compact solution, which results in the required mechanical stiffness and which allows an easy replacement of the handles and other mechanical components. A further positive aspect is that torque sensor, clutch portion and angular rotation sensor enable to record torques and rotation of the handles not only in the uncoupled but also in the coupled arrangement. The device of FIG. 1 may be used primarily for research purposes. The device of FIG. 2 is especially suited for the application as a training device.

FIG. 1 shows a schematic illustration of a preferred embodiment of the device. It comprises by the following components:

-   1) Exchangeable handles -   2) Main shaft (shown solid, implemented in a device by several     shafts and couplings) -   3) Variable slipping clutches (adjustable by hand) -   4) Angular rotation sensors to measure the angular position of the     handles. The sensors are mounted to the housing of a device. -   5) Torque sensors to measure the torque which is applied by the     subject. If the main shaft is locked in the middle, the sensors     measure only the torque at the left or right side, applied by the     left or right hand, respectively. When unlocking the main shaft,     both sensors measure the same torque. -   6) Optional locking of the main shaft. With a locking pin the user     is able to lock the main shaft. With a locked shaft both handles can     be rotated independently. -   7) Belt to translate the rotation of the handles to the angular     rotation sensors. This solution allows a compact design. -   8) Bearing of the main shaft, mounted to the housing of a device.

FIG. 2 shows a schematic illustration of a slightly modified embodiment of the device. This device comprises the following components

-   1) Exchangeable handles -   2) Main shaft (shown solid, implemented in a device by several     shafts and couplings) -   3) Variable slipping clutches (adjustable by hand) -   4) Angular rotation sensors to measure the angular rotation of the     handles. The sensors are mounted to the housing of a device on the     one side and to the handles on the other side. -   5) Torque sensors to measure the torque which is applied by the     subject. If the main shaft is locked in the middle, the sensors     measure only the torque at the left or right side, applied by the     left or right hand, respectively. When unlocking the main shaft,     both sensors measure the same torque. -   6) Optional locking of the main shaft. With a locking pin the user     is able to lock the main shaft. With a locked shaft both handles can     be rotated independent. -   8) Bearing of the main shaft, mounted to the housing of a device.

FIG. 3 shows a technical drawing of the device of FIG. 1. It comprises the following components:

-   1) Exchangeable handles -   2) Main shaft consisting of:     -   2.1) Coupling to connect the torque sensor with the slipping         clutch.     -   2.2) Shaft to connect the torque sensor with the slipping         clutch.     -   2.3) Perforated disc. Part of the locking system used to connect         the torque sensors. -   3) Variable slipping clutches (adjustable by hand) -   4) Angular rotation sensors to measure the angular position of the     handles. The sensors are mounted to the housing of the device. -   5) Torque sensors to measure the torque which is applied by the     subject. If the main shaft is locked in the middle, the sensors     measure only the torque at the left or right side, applied by the     left or right hand, respectively. When unlocking the main shaft,     both sensors measure the same torque. -   6) Locking pin to prevent the perforated disc 2.3) from rotating.     With that the whole main shaft is locked. When the main shaft is     locked, both handles can be rotated independently. -   7) Belt to translate the rotation of the handles to the angular     rotation sensors. This solution leads to a compact technical design. -   8) Ball bearings to support the holding fixtures 10 -   9) Housing -   10) Holding fixture for the handles

FIG. 4 shows the following examples of exchangeable handles of the device for unilateral and bilateral (non-cooperative or cooperative) hand movements:

-   a) Handle in form of a nut to simulate the movement of putting a     screw and a nut together. -   b) Handle in form of a pen to simulate the movement of open/close a     screwable pen. -   c) Handle in form of a crank handle. -   d) Handle with a lever. -   e) Handle with to pin simulating a different crank handle. -   f) Handle with a wheel. -   g) Handle with a plate. -   h) Handle to simulate a key. -   i) Handle to simulate a corkscrew. -   k) Handle to simulate the bottom of a bottle or a big handhold -   l) Handle to simulate the upper part of a bottle or a small handhold

EXAMPLES

The application of the device in the neurorehabilitation (e.g. stroke subjects) will be based on research studies to explore the effect of different manipulative tasks of both hands on the neuronal coupling/uncoupling of the two arms.

It is argued that by coupling manipulative movements of the hands by the device they become more efficiently performed. This is to be reflected in a stronger neuronal coupling of the arms on supraspinal and spinal levels (unilateral electrical stimulation of dig. II and V/ulnar nerve is followed by distinct reflex EMG responses in arm muscles of both sides).

A pilot study has been performed to asses if an unilateral nerve stimulation results in senseful bilateral arm muscle responses with the device of FIG. 1, by having the patient perform a movement equivalent to opening a bottle. FIGS. 5 and 6 show the task-specific EMG responses in hand flexor and hand extensor muscles on both sides following unilateral non-noxious ulnaer nerve stimulation of the right hand, averaged over 18 stimulations. The electrical stimulus was randomly released 100 ms after the onset of cooperative (coupled mode) and non-cooperative (un-coupled mode) hand movements. In the case of cooperative movements (FIG. 5), the EMG responses of the left hand muscles are significantly more distinct than in the case of non-cooperative movements (FIG. 6). This indeed indicates that ONE supraspinal control centre coordinates the cooperative hand/arm movements of both sides.

The device may also be applied for other investigations: Non-noxious electrical stimuli may be applied in a random order to the dig. II and V/ulnar nerve of the right hand, shortly after the start of an uni-(against the resistance force of the device instead of that of the contralateral hand) or bilateral opening/closing hand movement. Upper and lower arm muscle EMG activity is recorded from both sides. The reflex EMG responses to the stimuli are expected to be stronger in the muscles of both sides during a bilateral, cooperative task, indicating a neural coupling of the two arms.

In another setting, transcranial magnetic stimuli may randomly be applied to the hand area of the right hemisphere, (triggered) shortly after the start of the non-cooperative/cooperative movement. The EMG responses in the arm muscles of both sides are expected to be stronger in the cooperative task. This is based on 1. the anatomical evidence, that there are from each hemisphere strong neural connections to the contralateral-but also to the ipsilateral sides on supraspinal and spinal levels (14) which might play a major role during bilateral tasks and 2. on the fact of a task-dependent neuronal coupling of upper and lower limbs during locomotion (for review see (4)).

Furthermore, the device may be applied for rehabilitation purposes.

REFERENCES

-   1. Dietz, V. and J. Michel, Locomotion in Parkinson's disease:     neuronal coupling of upper and lower limbs. Brain, 2008. 131(Pt     12): p. 3421-31. -   2. Kloter, E., M. Wirz, and V. Dietz, Locomotion in stroke subjects:     Interactions between unaffected and affected sides. Brain, 2011: p.     submitted. -   3. Michel, J., H. J. van Hedel, and V. Dietz, Obstacle stepping     involves spinal anticipatory activity associated with quadrupedal     limb coordination. Eur J Neurosci, 2008. 27(7): p. 1867-75. -   4. Rosenzweig, E. S., et al., Extensive spinal decussation and     bilateral termination of cervical corticospinal projections in     rhesus monkeys. The Journal of comparative neurology, 2009.     513(2): p. 151-63. -   5. de Leon, R. D., et al., Locomotor capacity attributable to step     training versus spontaneous recovery after spinalization in adult     cats. Journal of neurophysiology, 1998a. 79(3): p. 1329-40. -   6. de Leon, R. D., et al., Full weight-bearing hindlimb standing     following stand training in the adult spinal cat. Journal of     neurophysiology, 1998b. 80(1): p. 83-91. -   7. Edgerton, V. R., et al., Use-dependent plasticity in spinal     stepping and standing. Advances in neurology, 1997. 72: p. 233-47. -   8. Dietz, V., Do human bipeds use quadrupedal coordination? Trends     Neurosci, 2002. 25(9): p. 462-7. -   9. Dietz, V., Body weight supported gait training: from laboratory     to clinical setting. Brain Res Bull, 2008. 76(5): p. 459-63. -   10. Liepert, J., et al., eds. Motor cortex plasticity during     constraint-induced movement therapy in stroke patients. Neurosci     Lett. Vol. 250. 1998: Ireland. 5-8. -   11. Taub, E., G. Uswatte, and T. Elbert, eds. New treatments in     neurorehabilitation founded on basic research. Nat Rev Neurosci.     Vol. 3. 2002: England. 228-36. -   12. Lo, A. G., et al., eds. Robot-assisted therapy for long-term     upper-limb impairment after stroke. N Engl J. Med. Vol. 362. 2010:     United States. 1772-83. -   13. Lum, P. S., et al., eds. Robot-assisted movement training     compared with conventional therapy techniques for the rehabilitation     of upper-limb motor function after stroke. Arch Phys Med Rehabil.     Vol. 83. 2002: United States. 952-9. -   14. Posteraro, F., et al., Robot-mediated therapy for paretic upper     limb of chronic patients following neurological injury. Journal of     rehabilitation medicine: official journal of the UEMS European Board     of Physical and Rehabilitation Medicine, 2009. 41(12): p. 976-80. 

1. A device to train bilateral, cooperative hand functions of a subject, said device comprising: housing means; handle means comprising two exchangeable handles, namely a left handle and a right handle; shaft means comprising multiple shafts and couplings for coupling said shafts, clutching means comprising variable slipping clutches, said slipping clutches being adjustable: first sensor means for measuring the angular position of each of said handles, locking means for locking said shaft means wherein both handles can be rotated independently when said locking means are locked; bearing means for said shaft means, said bearing means being mounted to the housing of the device; second sensor means for measuring the torque which is applied by the subject onto each of said handles.
 2. The device according to claim 1, wherein said locking means are positioned between said second sensor means so that said second sensor means for the left handle can measure the torque applied onto the left handle and said second sensor means for the right handle can measure the torque applied onto the right handle when the locking means are locked and said second sensor means for the left handle and said second sensor means for the right handle can measure the torque applied onto either of said handles when said locking means are unlocked.
 3. The device according to claim 1, wherein said sensors are mounted to said housing.
 4. The device according to claim 1, further comprising belt means to translate the rotation of said handles to said first sensor means.
 5. A method to train a subject, specially a person with rehabilitation needs, with a device according to claim 1, wherein said handles used are selected of the following: one or both handles in form of a nut to simulate the movement of putting a screw and a nut together, one or both handles in form of a pen to simulate the movement of open/close a screwable pen, one or both handles in form of a crank handle, one or both handles with a lever, one or both handles with to pin simulating a different crank handle, one or both handles with a wheel, one or both handles with a plate, one or both handles to simulate a key, one or both handles to simulate a corkscrew, one or both handles to simulate the bottom of a bottle or a big handhold, one or both handles to simulate the upper part of a bottle or a small handhold.
 6. Use of a device according to claim 1 for research studies to explore the effect of a plurality of manipulative tasks of both hands of a subject on the neuronal coupling/uncoupling thereof.
 7. The device according to claim 2, wherein said sensors are mounted to said housing.
 8. The device according to claim 2, further comprising belt means to translate the rotation of said handles to said first sensor means.
 9. The device according to claim 3, further comprising belt means to translate the rotation of said handles to said first sensor means.
 10. A method to train a subject, specially a person with rehabilitation needs, with a device according to claim 2, wherein said handles used are selected of the following: one or both handles in form of a nut to simulate the movement of putting a screw and a nut together, one or both handles in form of a pen to simulate the movement of open/close a screwable pen, one or both handles in form of a crank handle, one or both handles with a lever, one or both handles with to pin simulating a different crank handle, one or both handles with a wheel, one or both handles with a plate, one or both handles to simulate a key, one or both handles to simulate a corkscrew, one or both handles to simulate the bottom of a bottle or a big handhold, one or both handles to simulate the upper part of a bottle or a small handhold.
 11. A method to train a subject, specially a person with rehabilitation needs, with a device according to claim 3, wherein said handles used are selected of the following: one or both handles in form of a nut to simulate the movement of putting a screw and a nut together, one or both handles in form of a pen to simulate the movement of open/close a screwable pen, one or both handles in form of a crank handle, one or both handles with a lever, one or both handles with to pin simulating a different crank handle, one or both handles with a wheel, one or both handles with a plate, one or both handles to simulate a key, one or both handles to simulate a corkscrew, one or both handles to simulate the bottom of a bottle or a big handhold, one or both handles to simulate the upper part of a bottle or a small handhold.
 12. A method to train a subject, specially a person with rehabilitation needs, with a device according to claim 4, wherein said handles used are selected of the following: one or both handles in form of a nut to simulate the movement of putting a screw and a nut together, one or both handles in form of a pen to simulate the movement of open/close a screwable pen, one or both handles in form of a crank handle, one or both handles with a lever, one or both handles with to pin simulating a different crank handle, one or both handles with a wheel, one or both handles with a plate, one or both handles to simulate a key, one or both handles to simulate a corkscrew, one or both handles to simulate the bottom of a bottle or a big handhold, one or both handles to simulate the upper part of a bottle or a small handhold.
 13. Use of a device according to claim 2 for research studies to explore the effect of a plurality of manipulative tasks of both hands of a subject on the neuronal coupling/uncoupling thereof.
 14. Use of a device according to claim 3 for research studies to explore the effect of a plurality of manipulative tasks of both hands of a subject on the neuronal coupling/uncoupling thereof.
 15. Use of a device according to claim 4 for research studies to explore the effect of a plurality of manipulative tasks of both hands of a subject on the neuronal coupling/uncoupling thereof. 